This invention relates to an electronic sewing machine capable of producing a desired one or combination of stitch patterns with predetermined stitch control data thereof which may be selectively read out by the machine operator.
In an electronic sewing machine, a selected one or combination of stitch patterns can be produced with a predetermined stitch control data for determining the needle penetrating positions in series. For example, a triangular shaped pattern as shown in FIG. 1 has its own data comprising a set of coordinates A.sub.1 to A.sub.10, and a parallelogram shaped pattern as shown in FIG. 2 is produced with a set of coordinate determining data for the stitches B.sub.1 to B.sub.12. In this connection it is to be noted that for the purpose of sequentially producing the same pattern in series, the stitch control data for the last stitch (A.sub.10, B.sub.12) of each pattern will generally be coupled with the initial data for the first stitch (A.sub.1, B.sub.1). Thus, when the machine operator so desires, a plurality of the same pattern can be continuously produced as shown in FIG. 1 or 2.
Meanwhile, it may be often required to produce the lock stitches at the last stage of any pattern for the purpose of preventing the thread from being frayed or loosened. When the pattern of FIG. 1 is followed by the lock stitches, the lock stitches are started from the last point A.sub.1 which is stitched due to the initial address data for the first stitch A.sub.1 stored in the memory in combination with the stitch control data for the last stitch A.sub.10, thereby making it possible to produce the stitch pattern as desired, as shown in FIG. 3. However, in the last case of the pattern of FIG. 2 being followed by the lock stitches, the lock stitch has been undesirably produced from the stitching point B.sub.1 as shown in FIG. 5. In this case the lock stitch forming operation should preferably be commenced from the last stitching point B.sub.12 of the preceding pattern as shown in FIG. 4, which has, nevertheless, not been performed in the prior art.